Document RY7wg87rQoEoOb4EMvMo2GgX

Dial Comm Dept. Address Subject 6*234-227:) Date January 10, 1972 Dielectric Systems Laboratory, ISLO Pittsfield, Massachusetts BENEFITS OF PCB USE Mftssrs. J. T. Batty P. G. Benignus L. L. Dongier J. C. Dutton R. W. Frahra W. B. Gaither D. F. Haywood E. C. Hoffman T. H. Lea C. J. bieloun T. L. Mayes L. A. Morgan R. C. Osthoff Gentlemen: For your information a copy of a report is attached describing the benefits to the public arising from the use of polychlorinated biphenyls in tho electrical industry. This report together with a letter of trans mittal by J. F. McAllister (also attached) was sent to Dr. Edward J. Burger, Jr. of the Office of Science and Technology. Additionally, this report was also made available to the National Industrial Pollution Control Council at a meeting on January 3, 1972 and will also be made available to ANSI Com mittee C-107. It was prepared entirely by General Electric personnel (see attachment labeled "Preface" which was submitted with the report). It is our understanding that Westinghouse made a report entitled "The Need For Continued Use of Polychlorinated Biphenyls As Electrical Insulating Liquids" available to the National Industrial Pollution Control Council but did not submit it to the OST as we did. Copies of the Westlnghouse report will be forwarded as soon as available. Very truly yours, E. L. Rant, Manager Dielectric Systems Laboratory Building 11 - 315 Att. (3) .ml MOAjS 09179a a$ GcWEaAL^J ELSCTH3C GENERAL ELECTRIC COMPANY, 670 LEXINGTON AVENUE. NEW YORK. N. Y. 10022 Plioiw (212) TECHNICAL RESOURCES SUBJECT: Benefits of PCB Use December 30, 1971 Dr. Edward J. Burger, Jr. ' Executive Office of the President Office of Science and Technology Room 4224, New Executive Office Building Washington, D. C. 20506 Dear Dr. Burger: Accompanying this letter is a statement descriting the benefits to the public arising from the use of polychlorinated biphenyls in the electrical industry. It is submitted in response to your Invitation to prepare material for the consideration of the Office of Science and Technology in supporting the work of the Interagency Task Force on PCB. Whereas there is a growing body of literature on the wide dispersal, toxicology, and ecological significance of this class of materials, nowhere do we find adequate treatment of the unique proper ties which have occasioned its use in electrical apparatus, nor of the advantages of safety, reliability, and economy which have ensued. Our paper is offered to help remedy this lack and thereby assist in arriving at a balanced comparison of public risk with public benefit. There is ample indication that the environment carries a significant burden of some forms of PCB. This burden derives, we believe, in some measure from the untutored waste disposal practices of the recent past, but principally from the nonelectrical uses (e. g., as plasticizers in paints and plastic materials and as hydraulic and heattransfer fluids in industrial machinery). It1 is our belief that the pattern of restricted use, process control, and waste disposal engineering now being put in place by voluntary industry initiatives in the U. S. and England will, if adopted also in other PCB-producing countries, prevent significant increase in this burden. The key feature of this program is to limit HONS 0 9 1 7 9 9 GENERAL ELECTRIC Dr. Edward J. Burger, Jr. -2 - December 30, 1971 application to sealed electrical apparatus. Our calculations indicate that tho portion of electrical PCB possibly reaching the environment from field disposal and repair activities is being rapidly reduced and may be already below 1 percent of total electrical industry usage in the United States. In the near future, this class of waste should be the only category remaining, as effluent from manufacturing plants approaches zero and the nonelectrical applications are cut off at the source. The residual field waste from electrical apparatus is itself subject to further improvement, and ways to accomplish this are now under study by the C -107 Committee of ANSI. If these efforts succeed in preventing an absolute increase in I such discharges as the power industry continues to grow, the contribution I to the nation's total environmental burden would be so low as to require | more than a thousand years to double the burden. - > To the extent that this assessment is confirmed by further study and future developments, it would appear that we need have less concern for the technical problem itself than for the possibility of legislation or regulatory rulings which fail to take into account the special circumstances of electrical industry usage or the public benefits which would fall victim to any undifferentiated prohibition of PCB use. The attached report has been prepared by a team of General Electric scientists and engineers in less than two weeks, in accordance with your recommendation of a preliminary document at the earliest I>osslble moment. Accordingly It is neither exhaustive in its treatment nor completely consistent in the format of presentation for the various applications involved. . Please let us know if you or your colleagues desire more information on any of the points covered in the statement, or clarification of any obscurities, and we shall do our best to supply the deficiency. Thank you for the opportunity to introduce consideration of PCB benefits into the deliberations on this important public question. Very tml^yours JFM/rs Att. J. F. McAllister Manager-Product Quality Corporate Executive Staff General Electric Company HONS 091800 -3- INTRODUCTION Polychlorinated biphenyls (FCB) have been used In a wide variety of Industrial and consumer applications over the past 40 years, but It was only recently that evidence began to appear that these materials had been widely dispersed throughout the environ ment. By latter dated February lg, 1970 tha Monsanto Company, sole US producer of FCB's, notified all of Its customers of'the potential problam of environmental contamination" by these liquids and recommended "that all poaslble care should be taken In the application, processing, and effluent dlsposel of these products to prevent them becoming environmental contaminants." Monsanto has begun a program to discontinue sales of FCB's for use In paints, plasticisers, specialty Inks, adhaslves, paper coatings and all other open-aystam applications. Tha Monsanto Company has deelared, however, that It will continue to sell FCB's for closed-system electrical uses. This decision Is a tacit recognition of the Important role that FCB'a play In the aafe, reliable, and efficient delivery of electric power from the generating plant to the user. In the spate of published reports and statements thst have appeared In recent years on FCB' s thore has been no meaningful exposition of this role of FCB's In electrical equipment -- why, where, and how they are uaed; what alternatlvas are available; and what the consequences would be to Che users of such equipment If FCB's were no longer available. We hope that this report will provide such an HONS 0 9 1 0 0 1 -4BACKCROUND PCB't r* uaad by tha electrical industry ss component* of eartsin typas of tranaformora and capacitors. Tha natura and function of those devicos ara described in tha saparate sections of this roporC devoted to then. At this point It Is sufficient to say: 1. Transformers are devices for converting electrical povor from one voltage and current level to another, and tha conducting parts of these devices must be separated from each other by a suitable Insulating medium. 2. Capacitors ara devlcaa for storing electrical energy through the physical separation of charged metal surfacea by an insulating medium. Prior to 1930 the most commonly used Insulating medium was mineral oil. Tha early 1930's saw tha commercial development of lnaulatlng liquids that ware mixtures of synthetic chlorinated aro matic hydrocarbons, principally various polychlorinated biphenyls. By controlling the composition of these mixtures, the menufActurer could obtain desired combinations of thermal, chemical end dielectric properties that reaulted in Insulating liquids with much greeter oxidation and fire resistance than mineral oils. During the pest 40 years these liquids have become widely used in certain types of transformsrs end capacitors and are recognised ee a distinct class of Insulating matsrlals designated by the international term "askarel"* The definition of the term "askarol", the composi tions- of the liquid that comprise this class of matsrlals, end the various trademarks by which thsy. are known commercially ere described In the following section heeded "Askars!". ' ? 0 B T 6 0 SNOW -5Tho ptrtlcuUr askarel* uaad in transformers and capacitors aro different; to also ace Che reasons lor, and che excenc and consequence* ol, chelr use in these two types of electrical equip ment. However, certain general comments can be mado at this point concerning their use in both type* of equipment: 1. Askarel-lnsulated transformers and capacitors are delivered to eustomars as sealed units from which there is no eecape of askarel under normal operation during their expected lifetimes of 10 to more than 30 years. Howevor, certain types of equipment failures can rupture the ease and permit the loas of eorae askarel to the environment. Such falluree occur at a rate of about^^^l2/X^f the unita in aervlea per year. 2. FCB's can get into the environment during the menu- facture, delivery. Improper use, maintenance, repair, and disposal of transformers and capacitors. In ' addition to specific control measures instituted by individual manufacturers and racommendad by them to the equipment uears, tho American National Standarde Institute has established ANSI Committee C107 on Uee and Disposal of Askarel Used in Electrical Equipment, Its memberships (see Appendix 1) is E 0 8 T 6 0 SNOW divided Into separate working group* on transformers - and eapacltora which will recommend national atandards and procedures necessary to prevent the loss of PCB's to the environment at *11 stages from equipment r manufacture through ultimate disposal. 3. f The record of reliable and safe performance that I askarel-lnsulated transformers snd capacitors have I -6complled during Che past four decades Is reflected In the various codes, standards, and regulations th'at now effectively require p continued use of aakarel-lnsulated equipment In aiany applications. ONS 091804 -7 ASKARliL Dcfinltlona' la A Synthetic nonflammable insulating liquid which, whan decomposed by Cha alacCrlc arc, evolvea only nonflammable gaseous mixture!, (From the National Electrical Code 1971 and the American National Standarda Institute C-42 series, "Definitions of Electrical Terms.'*) 2, The term askarel generally describee a widely used, broad class of nonflammable eynthetlc haloganated hydrocarbon Insulating liquids used as electrical insulating madia. Askarels of various compositional types are used. Under arcing conditions the gases produced, while consisting of predomi nantly non-combustible hydrogen chloride, can yield varying amounts of combustible gaaes depending upon the aakarel type. Insulation systems Incorporating these askarels and celluloslc or other organic materials may, when arced, produce gaseous mixtures which are moderately flammable.. (From ASTM (American Society for Tasting and Materials) Method D 2283-71, Fart 29, 1971 Issue; will also appear In the 1972 Issue of the IEEE (Institute of Electronic and Electrical Engineers) "Guide for Acceptance and Maintenance of Transformer o Askarels In Equipment," Adoption was also recommended to the International Electrotechnical Commission by Its Subcommittee 10D (Insulating Liquids Other than Hydrocarbon Oils) of Committee 10 (Liquid and Gaaeoue Dielectrics) as reported In Item number 9 of mlnutos AM 1364/SC 10B. March 1971.) 5 0 B T 6 0 SNOW -8- Composit ions Polychlorinated biphenyls are derivatives of the hydrocarbon, biphenyl, which has the chemical formula ^^2H10* Prom one to fen of the hydrogen atoms in a molecule of blphonyl can be replaced by chlorine atoms, and the chemical Identity of the resulting chlorlnatad compound depends both on the number of chlorine atoms that have been introduced Into the molecule and on the specific sites in the molecular structure at which they are introduced. The commercial material manufactured by Monsanto under its registered trademark Aroclor consists of mixtures of theso specific chlorinated compounds. They are usually Identified by the weight percent of chlorine In tho totel mixtures, e.g. Aroclor 1234 con tains 342 chlorine. The Aroclors commonly used In the electrical industry are Aroclors 1260, 1234, and 1242. Aroclor 1242, used primarily in capacitors, contains about 72 of pentachloroblphanyls and higher. In September 1971 Monsanto Introduced a new capacltor-grede askarel, Aroclor MCS-1016, which is essentially Aroclor 1242 that has been specially processed to reduce the eontont of pentachloroblphanyls and higher to less than 0.42. As a general rule, the nonflammability of liquid FCB's, their vapors, end their arc-formed gaseous products is greater the higher the degree of chlorination of the liquid. Studies by Monsanto suggest that the resistance of PCB's to degradation In the environ ment may also Increase with increasing chlorine content. Analytical methods for low levels of FCB's (reported in pares per million or parts per billion) In marina, aquatic, and wildlife environments do not always Identify the spaclfic compounds that ere present, but In Its letter of February 19, 1970 to Its customers, Monsanto stated chat "FCB's with a chlorine content of loss than 342 have HONS 0 9 1 8 0 6 /V -9 not bon found in the environment and appear to pretent no potential problem to the environment." Trademarks ' The following trademark! are used by electrical manufacturer! to designate the aekarele uaed In their product!! Manufacturer Trademark Aerovox Hyvol Allis-Chalroers . Chlorextol American Corp. Abestol Cornell Dublller General Electric Kuhlman Electric Dykanol Pyrenol Saf-T-Kuhl Elemax Sangamo Electric Wagner Electric Weetlnghouee Electric Dlaelor Noflamol Inerteen Toxic and Biological Effect! of PCB's Systematic Investigations of the toxic and biological effects of PCB's have been undertaken only within the past few years, and tha description and evaluation of the results Is beyond the scope of this report. Some Investigators suggest that reports of certain toxic reactions may be caused by highly poisonous compounds (e.g. chlorinated dibenzofurans) found to be contaminants In soma PCB preparations. In the United States, medical records show that over a nearly 40-year period the only adverse health effects experienced by US workers axposad' to PCB's, either during the manufacture of these liquids or of electrical equipment containing these liquids ,have been limited to occasional cases of non-chronic ehlorocno or other temporary skin lesions or Irritations. HONS 0 9 1 8 0 7 -10TRANSFORMERS Definition , A traneformer 1* a device for transferring electrical energy from one alternating current circuit to another by electromagnetic meant. It haa no moving parte and performs its function by linking two electric current carrying circuits (the colls, usually copper wire) via a common magnetic flux carrying-circuit (the core, usually a special grade of iron). A transformer may be deaigned to effect a change in voltage or current from one circuit to the other or simply to obtain electrical energy from one electrical circuit without making a conductive connection between it and a second electrical circuit. The tranamlsslon of electrical energy from one point to another is essentially the transmission of a required number of kllovolt-amperea (kva). By means of transformers the kva's may be generated at a low voltage suitable for the windings of generators, stepped up to higher voltages and lower currents suitable for transmission of electricity over long distance wires, and than at the desired destination stopped down to a lower voltage and larger current suitable for utilisation by electrically powered equipment. The almost universal use of the alternating current system for the transsilaslon and dlatribution of electrical energy la largely due to this ability of transformers to link up circuits of different voltages and currents. Thus the generator, the transmission lines, the secondary distribution system, and finally the great variety of ultimate loads can each be operated at tha vol tage most suitable to its particular function. Without this unique ability of the transformer to adapt the circuit voltage to the individual require ments of the different parts of the system, the enormous development and progress in the tranamlsslon and distribution of alectrlcal energy during q tho past 80 years would ndt have been possible. 91808 -11Why Askarels are Used In Transformers The colls end core of most transformers are enclosed in sealed metal tanks that are filled with an Insulating liquid, usually mineral oil. Under certain conditions of sudden power surges high-current electric sres are produced Inside the transformer which can generate and Ignite flamnable and explosive gas mixtures formed from the mineral oil and other cellulosic In sulating components In the transformer. Becausa of the nonflammability of liquid askarels, their vapors, and their arc-formed gaseous products, transformers filled with askarels are free of these fire and explosion hazards and may be used In locadons where failures of oll-lnsulatad transformers would present a potential danger to life and `property. This safety factor ie the only advantage that askarelInsulated transformers have over oll-lnsulated transformers of the same size and rating. The density of askarels is about 1.7 times that of mineral oil, so askarcl-lnsulated transformers are heavier than their oil-filled counter parts. Askarels themsslves are more expensive than mineral oils, and their solvent characteristics require the use of more expensive Insulation compo nents on the Internal parts of the transformer, so the complete units sra more expensive. As a consequence, askarcl-lnsulated transformers have captured only those market applications (lass than 5%, but growing) where considerations of safety and reliability are paramount. Their use in such applications Is usually required or encouraged by the provisions of electrical codes, fire underwriting policies, or governmental regulations. Note; Prior to the mld-1950's the liquid used In askarel-lnsulatsd transformers was a SO-SO weight mixture of Arodor 1260 (601 chlorine) with trlchlorobcnzenes; then the benzene component was changed to a mixture of trl- and tetrachlorbenzenes; and In 1971 the Aroclor component was changed to Aroclor 1254 (547. chlorine). 6 0 9 T 6 0 SNOH . ' A/^ -12- Types and Applications of Askarcl-Insulatod Transformer* Thero are two broad classifications of transformers: powor transformers, which era usod to step up voltages; and distribution transformers, which are used to step down voltages. Ths many typos of transformers that are Included wlchln these two classifications are listed in Appendix 2, The applications that accompany the listing apply only to those units of a given type that are manu factured with askarel as the insulating liquid. Most units of- the types listed are still oll-lnsulatad. We estimate that the total number of askarel-insulated units that havo been put into service in the United States since 1932 is 125,000, and virtually all of these units are still in service. The llfetlme-before-fallure is often longer than 30 years, and almost oil units that do fall are rebuilt and returned to eerviea. The current production rate of new askarel-insulated transformers units is about 5,000 per year. . Most of these transformers are located inside public, commer cial, or industrial buildings; on the roof tops of such buildings; or in close proximity to such buildings, and require no special enclosures other than what are necessary to prevent accidental hazardous mechanical or electrical contact of persons with the equipment. However, the national Electrical Code does specify vaults for the indoor installation of askare1-insulated transformers rated more than 35,000 volts. Askarel-insulated transformers are limited by the olectrlal properties of these liquids to ratings 0 T S T 6 0 SNOW below 69,000 volts. The amount of askarel used in various types of transformers ranges from A0 to 500 gals. (516 to 6,450 lbs.) with an average of about 235 gels. (3,032 lbs.). During 1968, the last complete "normal" vear for the electrical industry, the total amount of -13l'CIl's used In traus formers was approximately 1.3 million gallons (B.4' thousand tons). 1*vcr.cnt Alternatives to Askarel-insulatcd Transf oriners 11 l'CU's were to be no longer available for closed-system electrical uses -- as they arc no longer available from Monsanto for open-system applications -- what alternatives to askarc1-Insulated transformers could now be supplied by the electrical industry, and what would be the effect upon the user should askarel-insulatcd transformers no longer be available either as new or replacement units? The only present alternatives to nskarel-lnsulated transformers arc oll-lnsulatcd transformers or dry-type transformers (either those open to the atmosphere or those that are gas-filled and sealed) - .i 'r ' A, Oil-insulated transformers ' 1. If one disregards safety considerations, there are no technical reasons why oil-insulated transformers could, not be directly substituted for askarel-insulatcd transformers. The size of the unit would be unchanged; , the weight and coat would be less, 2. There arc legal restrictions' to such a direct substitution. a. Some local regulations (e.g. Chicago) proliil> 1 e ' the use of oil-insula tod units in certain loca- ' tlons whore askarc1-insulated units are allowed TTBT60 SNOW b. Where oil-insulated transformers would not be specifically prohibited as ^on-site replacements for askarel-insulatcd units, the National Electrical Code imposes special restrictions upon their mode of installation. Although -1435,000 voles muse bo Installed In vaulcs, all oll-lnsulaead transformers rsqulrs vaulcs, ' except that alternative fire protection arrange ments are permitted for units rated not over 600 volts. Assuming that space were available Inside an existing building to accommodate these special auxiliary safety provisions, the cost of their construction could range from $5,000 to $50,000 per transformer, c. Oil-Insulated units can ba installed outdoore . if they are suitably Isolated from flammable structures or if these structures are suitably safeguarded against fires originating in the . transformers. The power output must then be brought to Che point of use Inside the building via cables or insulated buses, end the cost of cable and bus installation could also range from $5,000 to $50,000 per trans former. The outdoor transformer would have to be of a higher rating than the indoor one It would replace because of voltage drop and consequent power losses In the cable or bus runs, B Dry-type transformers - In most locations, dry-type transformers (either those 09181,; open to the atmosphere or those that are gas-filled and sealed) could not be directly substituted for askarel-Insulated transformers. There era several restrictions to such a direct substitution: -15- / 1. Tho provisions of the National Electrical Code ' are more stringent for certain classes of dry- type transformers than for comparable askarelinsulated units. 2. Present technology is not available for design ing and manufacturing reliable dry-type trans formers above jifciSS" KVA and/or 15 KV, 3. The reliability of dry-type transformers is less than that of comparably rated liquid-insulated transformers. Oil- and askarel-insulated units show much greater resistance to switching and lightning surges than do dry-type units. An ESI survey of failures in network transformer banks showed a 7% per year failure rate for dry-type units compared to 0.27. for liquid-insulated units. Furthermore, liquid-insulated transformers have a much greater overload capability. Many liquid-insulated units can sustain a 1001 ovirload for 8 hours and a 2007. overload for 2 hours. These transformers are able to maintain continuity of electrical service during periods of temporary outage of related equipment. . 4. Some dry-type transformers are larger by 10 to 30X than comparably rated liquid-insulated units, and most are more expensive. 5. Dry-type transformers are noisier by 5-10 d> than are liquid-insulated transformers. 6. Because their insides require regular cleaning, the maintenance costs for open dry-typa transformers are higher than those for sealed dry-type transformers C T 8 T 6 0 SNOW -16- or for liquid-insulated transformers, which are also scaled. 7. Open dry-type transformers, which are cheaper than sealed dry-type transformers, cannot be used In certain corrosive or hazardous atmospheres, e, g. on furnaces or on electrostatic precipitators near hot stacks. " Summary . 1. For technical or legal reasons It would be Impossible to replace most askarel-lnsulated transformers now in service by ol1-Insulated units of equivalent rating and reliability without major construction changes that would be required to compensate for the fire and explosion resistance of the askarel- lnsulated units, 2. For certain applications and locations, dry-type transformers could replace askarel-lnsulated trans formers, but with a significant reduction In system reliability. MUNS 091814 -17 CAPACITORS DaflnltIon , A capacitor Is a device that stores electrical energy. It consists of two metal surfaces or electrodes separated by an insulating medium such as air, paper, plastic film, or oil. When a voltage Is applied across the electrodes, electrostatic anargy la storad In the Insulating medium. In typical Industrial capacitors the electrode material Is aluminum foil and the Insulating medium or dlolectrlc Is paper tissue and/or plastic film,which for many applications Is Impregnated with a liquid dialoctrlc. A liquid lmpregnant Is used to fill the voids within the paper or plastic film structure, to fill the voids between sheets, and to contribute to the capacitance or charge carrying ability of the composite. Voids must be eliminated within capacitors that are to be used above 200-300 volts, which exceeds the dielectric breakdown strength of air. In our definition of transformers we emphasised their importance In the transmission and distribution of electrical power (kllovoltamparos) from the generating plant to the ultimate load. If the load wara purely resistive (e.g. an electric heating element) no furthar modification of the power supply delivered to It would be required. Other loads (e.g. induction motors) may require that a portion of the kilovolt-amperes delivered to tham be used to pro. vide a magnetising current, which does not contribute directly to the useful power output of the load. This portion of the total kva delivered to the load Is designated as reactive kilovolt-amperes (kvsrs). It has beon found sore economical to produce kvars from total kva's near the point of load rather than near the point of kva generation, and capacitors provide the most efficient vay of S T 8 T 6 0 SNOW -18cffecting this transformat Ion at the point of load. Why Askarcls are used in Capacitors Prior to 1930 moat 1tquId-f11led capacitors wara made with mineral oil. The subsequent substltution,o askarels for ralnoral oil made possible significant technical improvements In ths siis, reliability, and Ufa of these capacitors, A. Size The single most important property of a liquid to be used in a capacitor Is its dielectric constant (the ratio of its ability to store electrostatic energy relative to air). The dielectric constant of capac1 tor-grade askarel (Aroclor 1242) is 5,83 while that of mineral oil Is 2,25, When capacitor tissue is Impregnated with these liquids the dielectric constant of the paper-liquid composite Is 6.1 for . askarel and 2.9 for mineral oil. Furthermore, because of the relatively close match between the dielectric constants of cellulose, (6,6) and askarel (5.85) it Is possible to stress askaral-impregnated paper to 400-500 volts/mll., while the stresses that can be applied to comparable paper-mineral oil capacitors are limited to 300-350 volts/mll. The combined effect of these technical advantages of askarels has bean to permit a reduction of capacitor sizes to less than 14% of what theywere In 1924. In 1965 a new dielectric system consisting of paperpolypropylens film-askarol was introduced with stress capability up to 900 volts/mll. overall. Besldas . favorable strass distributions, the ability of askarel rhrt rtiftlectric strength of polypropylena 9 T 9 T 6 0 SNOW -19ls partly' responsible lor this improvement. B. Reliability end life Askarels are thermally and oxidatively more stable than mineral oils, and discharges, which can occur in capacitors, are less likely to ganerate gases from askarals than from mineral oils. The ehemical stability of askarels in the presence of capacitor tissue and plastic films and the favorable stress distributions hetween solid and liquid referred to above have made it possible .to design low-cost capacitors with a life expectancy of more then 10 . years life in lighting applications and more than 20 years in electric utility applications. In each application the first-year falluro rates are less than 0.2%. This level of life and reliability had not been achieved prior to the introduction of ' askarels. Furthermore, the non-flammability of askarels is greater than that of mineral oil, which reduces the fire hazard that might otherwise accompany those failures that result in rupture of the case. Whereas the transformer manufacturer has had to essentially "design around" the properties of MOWS 0 9 1 f l i 7 askarels in order to be able to take advantage of the safety factor that they impart to his equipment, tho capacitor manufacturer has been able to "design with" the properties of askarels and obtain significant technical improvements along with tho improved safety factor. As a.result askarals have virtually supplantad -20- No to : Prior Uo 1952 che liquid used in askare1 -imprognaCed capacitors was Aroclor 1254 (54% chlorine); it was than replaced by Aroclor 1242 (42% chlorine), which has better electrical properties and as noted in the. "Askarel" section, in September 1971 Monsanto Introduced a new capacitor-grada askarel, Aroclor MCS-1016, which is a modified Aroclor 1242. Unlika askare1 -Insulated transformers, the liquid in askarel-impregnated capacitors contains only Aroclors and does not contain added chlorobenzenes. Types and Applications of Aakarel-lmprcgnated Capacitors Tho principal types of askarel-lmpregnated capacltors. and their applications are described in Appendix 3. Almost 80 million such capacitors are manufactured annually, most of them for first time use. Unlike transformers, capacitors ara not rebuilt and rsturnod to service after failure. They are disposed of (see "Background" section, item concerning ANSI Commltte C107) and replaced by nsw capacitors. Capacitors used in lighting and elr conditioning applications 0.01 contain 0.005 to gals. (0,05 to 1.0 lbs.) of askarel per unit. The largest power capacitors contain about 6.7 gals (77 lbs.) of askarsl. The most popular size contains about 3.1 (36 lbs.) The National Electrical Code requires that any installation of capacitors in which any single unit contains more than 3 gallons of combustible liquid shall be in a vault like that required for transformers. .During 1968, the last complete "normal" yaar for the electrical Industry, the total amount of PCB's used in capacitors was approximately 14.4 thousand tons. HONS 091818 1* r c ii nit Alt c v n n i yen to At: ha r c. 1 -1 m pro p. n a t e d C a pacitora . If Tea's wore Co be no looser available for closed.system elcccrical uses -- as tHoy are no longer available from Monsanto for opon-ayctem applications -- what alcernnuivos to aakarol-lmpregnaced capacitors could now bo supplied by the electrical industry, and what would bo the effect upon the user should asksrcl-imprcgnatcd "eapacitors no lonscr be available either as new or replacement units? Possible alternatives to nskarol-impreghatsd capacitors are capaeitorn impregnated with mineral oil, or capacitors impregnated with certain other liquids, . A. Minor a 1 Oil Replacement of askarals by mineral oil would essentially roturn capacitor technology to its pro-1932 lovol. Some specific consequences of such a replacement would ba: 1. Safety. None of the possiblo liquid alternatives to askarals are nonflammable, and a fire hasard would be created by any capacitor failures that wero accompaniod by rupturo of the case. Presently the use of capacitors containing flammable liquid is governed by tbo National Electrical Code 'Articles 460 and SOI. - ' 2.' Site and Coot. A few specific examples will Illustrate the sixe and cast penalties associated with a switch from askarel to mineral oil in capncltoro. The most popular sisod power capacitors today aro rated ae 200 KVAR. If mineral oil were substituted for *0 nskarcl Che volume of Che capacitor would bo ^ . quadrupled a ml the dir act: lunar and meteriftl costs asr.oc in tccl with itn manufacture would lncreaoc by 70'4. Today power capncitoro arc available in 400 uvar MONS Q91A19 ijLi ^ <. '.> f, / ''" '`-*^<< '> KVAft bocauae of lncreaaed heat dlaaipatlon probloma with lncreaaed volume. In addition to lneroaaas In direct costs, tho power capacitor lnduatry would face incroaaad capital expanaaa aatlmatad at $2,000,000 to provide the lncreaaed volume of material at projected.KVAR requirementa. Steel companiea faced with lncreaaed alee, coat and flammability of capacitor banka for Induction heating furnacea would probably not Inatall new Induction heating capability, Utllltlea would have difficulty with tubatatlon-alee in crowded urban areaa. An lncreaae In the alee of capacitore for air conditioning would not be critical. In lighting appllcatlona a 3.75/.075 uf 540 VAC racing for high output appllcatlona la typical. If mineral oil were aubetltueed for aakarel, the capacitor would be 71% larger and materiale would coat 46% more. Lamp ballaet manufacturera would have to lncreaae the alee of Che ballaet to accommo date the larger capacitor. Thia would change the thermal performance of the unit and require U.L. approval of new ballaet deaigna. Lighting fixture manufacturera would alao face redealgn coata to 0918.20 cake larger ballaata. Reliability. Uaara of capacitore In all application areaa. have come to expect long life and very low Initial failure ratea. The preaent performance atan- </j derdc have been achieved after many ycara of field a * tcatlng and accelerated teatlng by manufacturora and uaera. The reliability of deaigna containing -2 3-. mineral oil in many applications would be uncertain. Available records show that capacitor reliability prior to tho availubility of askarel was only a fraction of whnt It is today. 4, Replacement Market. Tho implications of changes in capacitor size have been, discussed In terms of new designs. In each major application area aome capacitors are sold for replacement business. Power and induction heating capacitors are generally installed in recks of a few to thousands of capa citors. It would not be possible to make simple eube11tut ions for failed capacitore while main taining the system rating. In air conditioners replacement of felled capa citors might be as simple as installation of new brackets. On the other hand, tight designs might not take a larger capacitor at all. Lighting systems would be seriously affected by increases In capacitor size. Larger replacement ballasts would not fit Into existing fixtures without altered mounting arrangements. It is possible that space requirements would force complete replacement of lighting fixtures for the want of a replacement ballast. 5. Material Sources. Mineral oil is currently used in a relatively small number of specialty capaci tors. In this country there ie e single source of capacitor-grade mineral oil with limited facilities for acid refining of crudes from e single oil field. Increased demand would require HONS 0 9 1 8 ^ ., 99 -24- expanded facilities and investment and considerable development In defining technical requirements for capacitor-grade mineral oil. Efficient use of, mineral oil in capacitor designe would require higher density capacitor tissue than is currently produced in this country* At the least this would requires extensive paper machine modification* Capacitor winding techniques and machines would need to bo developed for winding tighter rolls* B Other Liquids . 1. Castor Oil* The dielectric constant of castor oil is 4*5 and this material is useful ss an Impregn&nt In D.C* energy storage capacitors* However, A.C. capacitors filled with this liquid have relatively short lives and are not very stable under A.C. discharges and in the presence of water derivable from the eelluloslc paper. 2* Dibutyl sebacate. This ester is especially useful in high frequency parallel plate capacitors because of its low, flat loss characteristics ovar a broad frequency range* In this type of construction the liquid is the sole dielectric material* When used in conjunction with paper, this ester is also unstable 3. Silicone Fluids* These materials have a dielectric constant of 2*7 and would generally be subject to .the same dlsadvantago a as mineral oil* C. Alternative Designs MGNb 0918 In addition to liquid dielectric eubetltutee, elternatlvea -25to Che paper-liquid dielectric might be considered. These would Involve the use of plastic film coated with aluminum foil or vapor-deposited aluminum as electrodes. Since the free volume of the system la less than that of paper the capacitance of tha system is less dependent on the dielectric constant of the liquid and the stress distribution between the plastle films and low dielectric constant liquids Is more closely balanced. Such dielectric systems are difficult to construct completely free of voids. It Is expected that several years will be required to achieve the required level of reliability in such dielectric systems NONS 09l8i3 -Z 0 ~ ' POSSltthK DKVKT.OPMKNT OF NEW TNSUI.ATTNC TJQUTPS The cosL* af nskorcl liquids Is About $2.00 per gallon, compared to about $0.30 per gallon for mineral oil. Thus, long before there were any environ mental concerns about PCll's there was a strong economic incentive to find other less-expensive insulating liquids with the desirable characteristics of nsknrcls. Since the 1930*8, at least 10 major chemical or electrical companies have invested large amounts of time and money in this search, all - with no success. There are today no fluids that can be uoed as one-for-one replacements for PCB's. . The continued search for new fluids would probably start with fluorochemlcals. Fluorochemlcals arc nonflammable, nbntoxlc, and as far b Is presently known represent no environmental hazard. High-boiling fluorochemlcals might thus be potential replacements for PCB's. Considerable laboratory study, over at least a one-year period, of the physical, chemical, and dielectric properties of these materials would be required in order to identify specific candidate materials. At least another year would be required to develop a finished product based upon a fluorochcmlcal. On one hand, the physical and dielectric properties would certainly be sufficiently different so that substantial engineering redesign by' MOMS 0 9 1 6 2 4 electrical manufacturers would be required to accommodate a fluorochemieal. On the other hand, a one-year lead time is needed to construct a chemical plant to produce the identified fluorochemieal in the millions of pounds that would be required per year. Furthermore, a significant program of environ mental tocting would be needed to ensure that the new material was indeed not an ecological hazard. The foregoing nro all highly optimistic time eetiraat The cost of manufacturing fluorochemlcals is inherently high. Prices of Da high-boiling liquids are $10 - 15 per pound, or*higher. At best one would Jiopc -t / - that In sufficient volume the price might approach that of Teflon, currently $3-4 per pound. Even thla optimistic figure is approximately twenty times the cost of PCB's, and since the value of FOB In.a transformer la roughly ono-tenth the total value of the transformer, the total cost of a fluorochemical-lnsulated transformer would be at least three times that of an equivalent askarel unit. 60 MON3 091825 -28- Appcndlx 1 Membership of ANSI Committee C107 on Use and Disposal of Asltarel Ued In Electrical Equipment Number of Representatives 2 2 1 1 1 1 2 ' X' 1 5 2 2 1 1 Organization Repreeented Department of the Army Environmental Protection Agency U.S. Department of Agriculture Tennessee Valley Authority General Services Administration National Bureau of Standarda Certified Ballast Manufacturers Association Edison Electric Institute Institute of Electronic & Electrical Engineers National Electrical Manufacturara Association Monsanto Company Commercial Waste Disposal Companies Engineering Consulting Firm Capacitor Manufacturer Serving as an Independent Member *) MONS 091826 Appendix 2 Types of Askarel-Insulated Transformers A. Distribution Transformers 1. Network (up to 2500 KVA) 2. Single- and three-phase (up to 2500 KVA) 3. Pole-mounted and station (up to 500 KVA) The application of thaae transformers In power distribution systems places a great premium upon their reliability and high overload capability (which they share with comparable oll-lnsulated unite): such as 1001 overload for 8 hours and 2001 overload for 2. hours. .4. Precipitation (high voltage DC) These transformers are part of the power supply for electrostatic precipitators, which are gaining Increasing use In preventing air pollution by particulate matter. They are generally Installed close to hot gaa stacks In an atmosphere that would be a fire haxard to oll-lnsulated transformers and a corrosion hazard to open dry-type transformers. Sealed dry-type transformers are impractical for high voltage DC. -. ` 1. Power Transformers 1. Secondary substation : a. Load center units b. Secondary substation generation unlta e. Switchboard units d. Integral unlta *0Ns neii e. Motor control unlta These5comprise the largest group of askarel-lnsulated transformera, and they find widespread application In the automobile, paper, -30- chemlcal, textile, steel, uonferrous metal, cement, mining, and petroleum induetriee. they ere ueed in commercial end public buildings, such es schools end hospitals; in defense end nuclear energy installations.; and by private and public utilities. 2. Master unit substation 3. Primary unit substation 4. Limited ampere substation 5. Industrial furnace . . These transformers are used in the hot, dirty atmosphere in proximity to glass melting and induction furnaces, which require high current, low voltage power supplies (more than 2300 KVA at no more than 13.8 KV). Existing technology does not permit construc tion of sealed dry-type transformers for these power ratings. 6. Rectifier These transformers are used for large rolling mills and DC industrial power supplies, and are covered by the same coiments given for industrial furnace transformers. 7. Transportation a. Third rail These transformers are used for rapid transit systems, and ara basically serving a rectifier function. b. Locomotive ' Prior to 1932, all on-board transformers were open dry-type. Because of problems with them, railroads went to askarel-lnsulated transformers. The changes in locomotive design since the 1930 e to o X would not now accomodate open dry-type transformers as replacements o v ia ta for askarel unit*. A recent trend has been to replace askarel by oil units, and thia will continue unless new DOT regulations require nonflammability. ' Multiple-unit car (MU) Theae transformer* are mounted under the flat-bed of paaaenger cars. They ride along in this location, about 8 inches above the rail, at apeeda up to ISO mph. The transformer must be ruggedly built to with stand the Impact of flying debris and constant vibration. Power to the cars is brought in through an overhead catenary end is fed to the underside of the cat where the transformer, controls, and propulsion equipment are located. Present voltage is 11 KV, but new electrification is expected to be 25 KV. Space and wolght are critical in this application. There are only about 33 Inches above the'rail. The width of the transformer is limited by the width of the car. Only oil- or askarel-lnsulated units would provide the required performance levels in the space available. As with locomotive applications, present DOT regulation* do not restrict the use of flammable liquids, and tha use of aakarel units has been dictated largely by the economic considerations of fir* Insurance rates. . moms q 91829 -32- ' Appendix 3 Typ of Aakarel-Inaulatod Capacitora Hinh Voltage Power , . Cene^ally AC capacitors are used to improve the power factor of a circuit. Power factor la the ratio of true power in watta to the apparont power aa obtained by multiplying the current flowing to the load by che circuit volcage. The power factor correction can ba made directly at the load or at utility subatatlons. In the latter caee high, voltage unite will be deaigned for 4,800 to 13,800 volt eervica. To the utility engineer tha uee of capedtore ir purely a matter of acondmica. The main beneflta that reault from tha uaa of capacitora are: 1. Reduction of loaaca aaeoclated with the delivery of electrl- cal power to tha point of uaa, 2. Reduction of the investment required in equipment for de livering electrical power to the point of uae, which may be broken down into: a. Reduction of current for the eame kilowatt load. b. . Reduction of the kva rating of equipment required to ' handle the eame kilowatt load. c. Reduction of the voltage drop for a given kilowatt load. d. Control of delivered voltage if the capacitor kva le varied. Electric utllitiea alao uae capacitor banks in aerlea with dlatrl- butlon clrculte to Improve voltage regulation. High voltage utility capacitora, low voltage power capacitora, and Induction heating capacitora are manufactured at tha rata of 200,000 par year, about 2 to 31 of which are for replacementa; the balance are for new inatallatlona. HONS 0 9 1 8 3 0 -33- B. Low Voltaea Pewar Capacitors Installed In Industrial plants at the demand site (typi cally large motors and welders) are designed for 230 to 575 volt service. Capacitors installed near the loads are the.most efficient way to supply the magnetizing currant to produce the flux necessary for the operation of Inductive devices. Rates for the sale of power are generally struc tured to encourage power factor correction at the site, eliminating the noed for the electric utility to transmit both power-producing current and magnetizing current ail the way from the generator to the plant site. The same considerations apply to Induction heating applications, the principal difference being that capacitors for this rapidly growing appli- ' cation are designed for operation at 960 to 9600 Hz. C. . Lighting Capacitors Improve the efficiency of lighting systems. A fluorescent or mercury vapor lamp can be ballasted without the use of a capacitor, but the power factor of the lighting system would then be in the range of SO to 60%. For commercial or Industrial lighting with either fluorescent or high Intensity discharge lamps, the use of a capacitor In the circuit provides part of the lamp ballasting and brings system power factor into the range of 90 to 95%. The current market for these applications is about 44,000,000 units annually of which about 10% are estimated to be replacement ballasts. D. Air Conditioning As in the lighting applications, the capacitor Improves system effi ciency. Air conditioners could be made to operate without capacitors, as do home refrigerators, but because of the higher capacity required for current elr conditioners, the resultant line/would virtually eliminate home "plug* ins" and would still further overburden a seriously threatened national MOMS 0 9 1 8 3 1 powar natwork. Almost all air conditioner pump motors are of the split winding type on which the capacitor provides phase differential for Che so-called start winding, thus delivering good starting torque. The proper size capacitor permits high (90% ) power factor after start-up. The current market for this application is about 12,000,000 units an nually, with about 5% of these estimated to be for replacement usage. Industrial Electronics This market catagory is a catchall covering many varied applications, two Important ones being motor run and power supply applications. Motor run applications are for pumps, fans, and farm feed equipment, and do not differ significantly from air conditioning applications. The power supply market uses capacitors principally to provide high power factor, but through careful design the capacitor can also provide wave ahaplng where desired. The market is estimated at 23,000,000 units per year with no estimate as to the relative size of the replacement isarket. MQNS 091832